Golang: how to sum an array of integers as strings and numbers - string

Question

How to sum an array of integers with mixed types of strings and numbers in GoLang?
Code below errors with "mismatched types int and any" and "cannot initialize 1 variables with 2 values".
Is there something like this JavaScript solution?
Function that sums array numbers (including numbers as strings)
errored code:
import (
"fmt"
"strconv"
)
func main() {
fmt.Println(sum([]any{9, 1, "8", "2"})) // this should output 20
}
func sum(arr []any) int {
n:=0
for _, v := range arr{
temp:=strconv.Atoi(v) //err: cannot initialize 1 variables with 2 values
n+=temp //err: mismatched types int and any
}
return n
}
This also errors:
n:=0
for _, v := range arr{
temp:=0
if reflect.TypeOf(v)=="string"{
temp=strconv.Atoi(v)
} else {
temp=v
}
n+=temp
}
return n

Answer 1

count+=temp //err: mismatched types int and any
Use a type switch to handle integer and string values as appropriate.
temp:=strconv.Atoi(v) //err: cannot initialize 1 variables with 2 values
strconv.Atoi returns two values. Assign the result to two variables. Handle the error return.
Here's the code with the fixes:
func sum(arr []any) int {
n := 0
for _, v := range arr {
switch v := v.(type) {
case int:
n += v
case string:
i, err := strconv.Atoi(v)
if err != nil {
panic(err)
}
n += i
default:
panic(fmt.Sprintf("unsupported type %T", v))
}
}
return n
}
For completeness, here's a version of the function that uses reflection. The type switch version of the function is preferred over reflection.
func sum(arr []any) int {
n := 0
for _, v := range arr {
v := reflect.ValueOf(v)
if v.Kind() == reflect.Int {
n += int(v.Int())
} else if v.Kind() == reflect.String {
i, err := strconv.Atoi(v.String())
if err != nil {
panic(err)
}
n += i
} else {
panic(fmt.Sprintf("unsupported type %s", v.Type()))
}
}
return n
}